Mark Brown is the Director of Safety Critical Systems at Parry Labs. Parry Labs develops multiple types of soft-updatable modularity for vehicles and avionics, in order to promote a Modular Open Systems Approach (MOSA). Mark has worked with a range of operating systems, type-1 hypervisors, and chip/system architectures to address a variety of high assurance concerns, including cybersecurity and flight safety. He first worked with Xen source code in a DARPA-funded collaboration with Adventium Labs (now Galois). In that project, we evaluated single event effects (SEE) for spacecraft that relied on Xen on x86. Since then, he has worked at Siemens, Lynx Software, and Collins Aerospace to promote modularly-updateable solutions.